<!DOCTYPE HTML>
<html>
    <head>
        <title>My WebSocket</title>
    </head>

    <body>
    Welcome<br/>
    <input id="text" type="text"/>
    <button onclick="send()">Send</button>
    <button onclick="closeWebSocket()">Close</button>
    <div id="message">
    </div>
    </body>

    <script type="text/javascript">
        var websocket = null;

        //判断当前浏览器是否支持WebSocket
        if ('WebSocket' in window) {
            websocket = new WebSocket("ws://localhost:8081/websocket/114514");
        } else {
            alert('Not support websocket')
        }

        //连接发生错误的回调方法
        websocket.onerror = function () {
            setMessageInnerHTML("error");
        };

        //连接成功建立的回调方法
        websocket.onopen = function (event) {
            setMessageInnerHTML("open");
        }

        //接收到消息的回调方法
        websocket.onmessage = function (event) {
            setMessageInnerHTML(event.data);
        }

        //连接关闭的回调方法
        websocket.onclose = function () {
            setMessageInnerHTML("close");
        }

        //监听窗口关闭事件，当窗口关闭时，主动去关闭websocket连接，防止连接还没断开就关闭窗口，server端会抛异常。
        window.onbeforeunload = function () {
            websocket.close();
        }

        //将消息显示在网页上
        function setMessageInnerHTML(innerHTML) {
            document.getElementById('message').innerHTML += innerHTML + '<br/>';
        }

        //关闭连接
        function closeWebSocket() {
            websocket.close();
        }

        //发送消息
        function send() {
            var message = document.getElementById('text').value;
            websocket.send(message);
        }
    </script>
</html>
